Hypertension is when blood pressure is too high. Blood pressure is written as two numbers. The first (systolic) number represents the pressure in blood vessels when the heart contracts or beats. The second (diastolic) number represents the pressure in the vessels when the heart rests between beats. High blood pressure usually develops over time. It can happen because of unhealthy lifestyle choices, such as not getting enough regular physical activity. Certain health conditions, such as diabetes and obesity, can also increase the risk for developing high blood pressure. There is no cure for high blood pressure. But treatment can lower blood pressure that is too high. If it is mild, high blood pressure may sometimes be brought under control by making changes to a healthier lifestyle.